麻豆约拍

Africa's huge mineral riches continue to draw investors - with reports in the last few days that China is making a seven billion dollar deal with Guinea, swapping oil and mineral rights for huge investment in infrastructure.

Trouble is, there's been an upsurge in disputes between mining companies and the governments of some of Africa's poorest and most volatile countries, such as Congo and Guinea.

The question is: will companies' contracts hold good? What happens when a new government comes into power, says the old licences were awarded improperly and wants to rewrite them?

One of the African countries where this happened is Liberia; we hear from the President of Liberia, Ellen Johnson-Sirleaf, and from Sir Mark Moody-Stuart, the former non-executive chairman of mining group Anglo American.